Hi Folks,
I am a Master student, trying to build an app in POX.
I am trying to respond to DNS query in the controller by creating response
dns packet with answer. But it is not working.
Here is my code :
#Create DNS Response message
91 dns_resp = dnsp()
92 dns_resp.qr = 1
93 dns_resp.aa = 1
94 dns_resp.answers.rdata = IPAddr('10.0.0.9')
95 dns_resp.questions = dns.questions
96 dns_resp.id = dns.id
97 dns_resp.total_questions = dns.total_questions
98 dns_resp.total_answers = 1
99
100 udp_req = event.parsed.find('udp')
101 udp = udpp()
102 udp.srcport = udp_req.dstport
103 udp.dstport = udp_req.srcport
104 udp.len = len(dns_resp) + udpp.MIN_LEN
105 udp.csum = udpp.checksum()
106 udp.set_payload(dns_resp)
107
108 ip = ipv4p()
109 ip_req = event.parsed.find('ipv4')
110 ip = ip_req
111 ip.srcip = ip_req.dstip
112 ip.dstip = ip_req.srcip
113 ip.set_payload(udp)
114
115 eth = ethernet()
116 eth.type = ethernet.IP_TYPE
117 eth.dst = event.parsed.src
118 eth.src = EthAddr("00:01:43:00:00:05")
119 eth.set_payload(ip)
120
121 msg = oflow.ofp_packet_out()
122 msg.in_port = event.parsed.in_port
123 msg.data = eth.pack()
124 action = oflow.ofp_action_output(port = oflow.OFPP_IN_PORT)
125 msg.actions.append(action)
126 self.connection.send(msg)
127 print "Succesfully sent dns response !"
128
Thanks
Anil
